Ophthalmic compositions containing alginic acid salts of pilocarpine,atropine and physostigmine



Patented June 17, 1969 D-mannuronic acid of colloidal dimensions, is available 3,450,814 commercially in a wide molecular weight range so that OPHTHALMIC COMPOSITIONS CONTAINING the viscosity of the salts of this invention can be varied ALGINIC ACI SALTS F PILOCARPINE to some extent by selection of an alginic acid of ap- ATROPINE AND PHYSOSTIGMINE propriate molecular weight. Arthur W. Bechtold Boonton and Vincent J. Rizzo North hfington, N assignors to Chemway 5 Algmlc acid is described 1n an article by Arnold B.

poration, Wayne, N.J., a corporation of Delaware t and wiiliam 2 MFNeEIY entitleid Organic D e- No Drawing Filed July 1964, 382,963 rivatlves of Algln Ac1d WhlCh appeared 1n lndustrlal and I C A61 27/00 Engineering Chemistry, vol. 43, pages 2073-2077, for US. Cl. 424-180 6 Claims September 1951. The structure given therein is as follows:

O=CI}OH III lil 0=C-OH 0 O C o 0' O H H H H H (I? LII III O=COH x ABSTRACT OF THE DISCLOSURE In an article by Arnold B. Steiner and William H. The invention relates to isotonic aqueous ophthalmic ehtltlad, g h 11 R VleW, appearing in Adsolutions containing atropine alginate or pilocarpine vancfts 1h Chemlstry es, v01- 11, pages 6-82, (l 95 1), alginate or physosfigmine a1ginate published by the American Chemical Society, 1t is indicated that in the above formula x ranges from 180 to 30 930 and that the molecular weight ranges from about This invention relates to new compositions of matter, 32000 to 200,000; to ophthalmic preparations containing them, and to Salts of a lhvehtloh a formed y mlxlhg the methods for their manufacture. The new compositions of water'lhsolhhle alglhlc 9 W1th ah q h Solutloh b matter are the alginic acid salts of pilocarpine, atropine suspehsloh 0f the aloid base In approximately equivand physostigmine or eserina alent molecular proportions. The reaction proceeds at The alkaloids pilocarpine, atropine and eserine have room temperature, although somewhat higher or lower long been known to have ophthalmic properties; pilotemperatures can be employed, and at normal pressures. carpine and eserine possess miotic activity and atropine The PH of the aqueous admixture of dlspersloh 0f alglhlc possesses mydriatic activity. These alkaloids have been 'f about and upon addition of the base, the P usedinthe form of aqueous solutions of the hydrochloride 1s ralsed- The Slope of the curve defined y P as to and other Salts, f both organic and inorganic acids. In ordinate andthe concentration of base as the abscissa is the treatment of certain eye disorders, such as glaucoma greatest Wlthlh a P range about t 8-0 and this and iritis, it is often desirable that the ophthalmic prepthe range Where the Salt n a i n in the Solution aration be in prolonged contact with the eye, as for ex- 15 greatest P Ophthahhlb Preparatlons, however, an ample, overnight, and for this reason the active materials excess of base is often deslfable, d hence th PH can have been incorporated into ointments. Ointments, howf hp t0 bq SuCh solutlons can be made ever, are inconvenient to use and the active material is lsotohlc y 'addltloh P C ride '01 Other salts. merely suspended in the ointment base. More recently, The w COIIIPOSIUOIIS f S in ent n can include aqueous isotonic solutions containing the active material preservatlvbs such as Ph y mercuflc a a P y together i Water S01ub1e thickening agents, Such as mercuric nltrate, and thimerosal, and aI'IlZI-OXIdBIItS such methylcellulose and carboxymethylcellulose, have been as sftdluh'l stflfite Sodlllm blsulfite 1n the cas of the employed but in such preparations the active material is esanhe SOhItlOH- merely di l d i h thi k d 1 i This invention is illustrated by the following examples. It has now been found that pilocarpine, which is water- In all Of the eXahlpleS, the alginic acid p y Was soluble, and atropine and eserine, which are poorly watercommercial alginic acid in the form of a White, fibrous soluble, form water-soluble salts when reacted with Powder haViIlg a P of about 3 in a 3% Water dispersion alginic acid, which acid is substantially water-insoluble. and an equivalent Weight of about It has been found that aqueous solutions of the salts of the invention surprisingly provide a dramatic increase EXAMPLE 1 in duration of miotic and mydriatic activity, as compared Into a one liter flask containing about 400 cubic cento prior solutions. Moreover, this increase in duration is timeters of water were introduced with stirring 4.505 obtained with solutions of the salts of the invention that grams of pilocarpine and 6.1 grams of alginic acid. 0.05 are less viscous than the prior solutions which have been gram of thimerosal (0.01%) was added and then distilled thickened with methylcellulose or other gums. Thus new Water was added to provide a total volume of 500 cubic and improved water-soluble, ophthalmic preparations are centimeters. The pH of the resulting solution was 5.9 and provided by aqueous isotonic solutions of the salts of this after a period of several weeks in a 40 oven the pH of invention. Alginic acid, which is a polymer of anhydro-fi the solution was 5.6. The assay of the final solution of pilocarpine alginate for pilocarpine showed 101% the theoretical amount of pilocarpine.

EXAMPLE 2 Four grams of pilocarpine were dissolved in 200 cubic centimeters of distilled water and the solution was separated into two 100 cubic centimeter aliquots.

To the first aliquot were added 2.5 grams of alginic acid with stirring. The pH of the resulting solution was 7.2. To this solution were then added 1.4 grams of sodium chloride and the aliquot was diluted to 200 cubic centimeters with distilled water. Thimerosal was added to the final solution in the amount of one part to 10,000 parts of solution. This was sample R-752 and assayed 100% of the theoretical amount of pilocarpine.

To the second aliquot was added suflicient dilute hydrochloric acid to adjust the pH of the solution to 7.2. TO this solution were then added 1.4 grams of sodium chloride and sufiicient distilled water to provide 200 cubic centimeters of solution. Benzalkonium chloride in the amount of 1 part to 10,000 parts of solution was added as a preservative. This was sample R-751 and assayed 104% of the theoretical amount of pilocarpine.

A drop of the pilocarpine alginate solution, R-752, was instilled into the eye of a cat and a drop of the pilocarpine hydrochloride solution, R-751, was instilled into the other eye of the cat. The pilocarpine alginate solution produced a dramatic increase in miotic response when compared to the pilocarpine hydrochloride solution. The difference in miotic response could be observed with the naked eye for four hours.

EXAMPLE 3 Into a one liter flask containing about 400 cubic centimeters of water were introduced with stirring 4.505 grams of pilocarpine and 6.375 grams of alginic acid. 0.05 gram of thimerosal was added (0.01%) and then distilled water was added to provide a total volume of 500 cubic centimeters. The pH of the resulting solution was 4.9. Sodium carbonate in the amount of 3 grams was added and the pH of the resulting solution was 5.3. The assay of the final solution of pilocarpine alginate for pilocarpine showed 100% of the theoretcal amount of pilocarpine.

EXAMPLE 4 Atropine alginate was prepared by dissolving 0.833 grams of atropine in 100 cubic centimeters of water to which was added one gram of alginic acid (preparation R-770). The pH of the resulting solution was 6.8. A drop of this solution was instilled into the eye of a cat and a drop of a commercial solution of atropine sulfate with an equivalent atropine "base content was instilled into the other eye of the cat. The mydriatic response to the atropine alginate solution lasted ten days or five times as long as the mydriatic response to the atropine sulfate solution (two days).

EXAMPLE 5 Physostigmine alginate was prepared by dissolving 1.10

or longer duration than physostigmine salicylate of equivalent physostigmine content.

EXAMPLE 6 Into a flask containing about 1,000 cubic centimeters of water were introduced with stirring 18.00 grams of pilocarpine and 27.43 grams of alginic acid. To this solution of pilocarpine alginate 13.4 grams of sodium chloride and 0.2 gram of thimerosal were added. Distilled water was added to provide a total volume of 2,000 cubic centimeters. The pH of the resulting solution was 4.1 and sodium carbonate was added to bring the pH of the solution to 5.72.

What is claimed is:

1. A composition comprising an isotonic aqueous solution of a material selected from a class consisting of pilocarpine alginate, atropine alginate and physostigmine alginate, the solution having a pH within the range of about 4.5 to 9.0 and being ophthalmically effective.

2. A composition comprising an isotonic aqueous solution of pilocarpine alginate having a pH within the range of about 4.5 to 9.0 and being ophthalmically eflective.

3. A composition comprising an isotonic aqueous solution of atropine alginate having a pH within the range of about 4.5 to 9.0 and being ophthalmically effective.

4. A composition comprising an isotonic aqueous solution of physostigmine alginate having a pH within the range of about 4.5 to 9.0 and being ophthalmically effective.

5. An ophthalmic preparation containing an ophthalmically effective amount of an isotonic aqueous solution. of a material selected from the class consisting of pilocarpine alginate, atropine alginate and physostigmine alginate.

6. An ophthalmic preparation containing an ophthalmically effective amount of an isotonic aqueous solution of pilocarpine alginate.

References Cited UNITED STATES PATENTS 2,547,653 4/1951 Minnis et al. 167-59 2,703,777 3/1955 Feinstein et al. 167-59 2,906,665 9/1959 Doyle 260209.6 X 2,962,499 11/1960 Weiner et al 260-292 3,049,548 8/1962 Sletzinger et al 260309 3,073,831 1/1963 Archer et al. 260-292 3,133,083 5/1964 Hester 260-319 3,169,971 2/1965 Sletzinger et al. .260-309 3,161,654 12/1964 Shen 260-319 FOREIGN PATENTS 604,255 8/ 1960 Canada.

OTHER REFERENCES Ouer, Annals of Allergy, May-June 1951, pp. 346-353. Graham et al., Journal 10f Pharmaceutical Sciences, vol. 51, No. 10, October 1962, pp. 988-992.

ALBERT T. MEYERS, Primary Examiner.

VERA C. CLARKE, Assistant Examiner.

US. Cl. X.R. 

